Climatic characteristics of Cixi

Cixi is located in the southern edge of the north subtropical zone and has a monsoon climate. Four distinct seasons, slightly longer in winter and summer, slightly shorter in spring and autumn. The average annual sunshine hours are 2038 hours, and the annual sunshine percentage is 47%. The annual average temperature 16.0℃ is the highest in July with an average of 28.2℃ and the lowest in June with an average of 3.8℃. The historical extreme maximum gas temperature is 38.5℃ and the lowest is -9.3℃. There is sufficient rainfall, with an average annual precipitation of 1.272.8 mm and an average annual runoff of 5 1.22 billion cubic meters. The peak month of precipitation is September, accounting for 65438 0.4% of the annual precipitation on average. Northwest to north wind prevails in winter, east to southeast wind prevails in summer, and easterly wind predominates throughout the year, with an annual average wind speed of 3m/s and an annual average windy day of 9.6 days. There are many tropical storms in summer and autumn. The disastrous climate in China is dominated by water, drought, wind and tide, and the temperature is abnormal.

Cixi has abundant rainfall, but due to its large population, uneven distribution of precipitation in time and space, and weak surface water storage capacity, the annual per capita water possession is only 578 cubic meters, accounting for 24% of the per capita water possession in Zhejiang Province. Cixi is a serious water shortage area, and the contradiction between supply and demand of water resources is prominent. Cixi inland waters are 6 1.75 square kilometers, accounting for about one tenth of the total area. There are 73 long rivers with a length of 770 kilometers, and the riverbed gradient is gentle, with an average water depth of 1.2 ~ 1.4 meters. Most north-south rivers flow northward into the sea, mainly including Songpu, Guyaopu, Yanpu, Shuiyunpu, Sizaopu, Sansong River and Zhoujialu River. The east-west rivers mainly include Huichuan River, Henghe Highway, Donghe River, gutang River, Sitang River, Liutang River and Tangqi River. The total length of large and small canals is 5,400 kilometers, and the normal storage capacity is 37.76 million cubic meters. At present, there are three lakes and reservoirs130,000 cubic meters in China, namely Fengpu Lake, Linghu Lake, Yaohu Lake, Changxi Reservoir, Waidu Lake, Lidu Lake, Baiyang Lake, Shanglin Lake, Humei Lake and Shaoao Lake, and three coastal reservoirs with a total storage capacity of 7,653. There are also 5 small reservoirs, 5 shantang 154, with a total storage capacity of 1855600 cubic meters. Groundwater resources are scarce, and the exploitable fresh water resources are only 7.82 million cubic meters per year.